546 Royal Society : — Mr. G. Gore on the 



ten days ; it had then acquired a superficial green colour. Molybdic 

 acid in powder turned dark green, but remained undissolved at the 

 end of nine days. Native sulphide of molybdenum remained un- 

 dissolved and apparently unchanged during two days. Molybdate 

 of ammonia in powder became yellowish green in the gas ; it became 

 grass-green in colour in the liquefied acid, but did not dissolve in 

 four days. Sesquioxide of chromium in powder did not dissolve in 

 six days, but became of a dull blackish-brown colour. A fragment of 

 anhydrous yellow chromate of potash became red before the gas 

 liquefied, but did not dissolve or otherwise alter in the liquid acid. 

 Sesquioxide of uranium became of a paler yellow colour in the gas, 

 but did not dissolve in the liquid acid in six days ; the residue was 

 entirely soluble in water. Precipitated black oxide of manganese in 

 powder, and free from water, became quite white in the gas ; it re- 

 mained white in the liquid acid without evolving visible bubbles of 

 gas, and did not lessen in bulk in seven days. A crystal of perman- 

 ganate of potash softened and swelled in the liquid acid, but did not 

 dissolve in five days ; it remained of a dark colour ; the residue 

 placed in distilled water produced no coloration. 



A. crystal of metallic arsenic remained perfectly bright and un- 

 changed, in bulk during three days' immersion. Arsenious acid in 

 powder quickly liquefied in the gas, and dissolved to a colourless 

 solution in the liquid acid. A crystal of arsenic acid softened before 

 the gas liquefied, and dissolved quickly and freely in the liquid acid 

 to a colourless solution. Bisulphide of arsenic in powder did not 

 dissolve in six days, but became slightly less red and more yellow; 

 a slight yellowish-white sublimate occurred in the tube during the 

 generation of the gas. Teriodide of arsenic in powder slightly dis- 

 solved to a purple-red liquid ; apparently only a trace of its iodine 

 was extracted, as its bulk was not visibly less in three days. A crystal 

 of bright antimony remained perfectly bright and unchanged after 

 nine days' intermittent immersion. Precipitated teroxide of anti- 

 mony became partly liquid before the gas liquefied ; it dissolved in 

 the liquid acid quickly and rather freely, and made a colourless 

 solution. A fragment of precipitated antimonic acid did not dissolve 

 in six days. A fragment of black tersulphide of antimony evolved 

 a film of yellowish- white sublimate, and lessened in bulk before the 

 gas liquefied ; it decomposed and dissolved in the liquid acid in about 

 a quarter of an hour, and formed a colourless solution which exhi- 

 bited no further change during seven days. A fragment of bright 

 metallic bismuth remained undissolved and unchanged in the liquid 

 during three days. 



Bright zinc evolved no visible gas in the liquid acid, and was not 

 perceptibly corroded in three days. Oxide of zinc slowly dissolved 

 in seven days. Metallic cadmium evolved no gas in the liquid 

 and was not sensibly corroded in three days. Precipitated car- 

 bonate of cadmium evolved no visible gas in the liquid acid, and 

 remained undissolved and unchanged in appearance during seven 

 days. Yellow sulphide of cadmium evolved a trace of white subli- 

 mate before the gas liquefied ; in the liquid acid it became quite 





